Question

我有一个包含以下字符串数据的文件

...
v -0.570000 -0.950000 -0.100000
v 0.570000 -0.950000 -0.100000
v -0.570000 -0.760000 -0.100000
v 0.570000 -0.760000 -0.100000
...
f 34 22
f 3 35 3
f 345 22
f 55 632 76
f 55 632
....

我希望从这个文件中提取以＆＃39; v＆＃39;开头的行中的所有数字。并且＆＃39; f＆＃39;。我已经写了以下正则表达式。

v(?:\s([0-9\-\.]+))+

Output:
group 1: -0.100000

f(?:\s([0-9]+))+

Output:
group 1: 22

但是你可以看到输出只是从每一行中提取最后一个数字，我想要输出如下：

Output:
group 1: -0.570000
group 2: -0.950000
group 3: -0.100000

Output:
group 1: 34
group 2: 22

有人可以帮我吗？

Answer 1

这是我最终使用的解决方案，以防有人需要它。

我使用了两个Regex而不是像上面评论中所建议的那样使用字符串拆分。

public class ObjParser {
    private static final Pattern vertexLinePattern = Pattern.compile("^v\\s(.+)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE);
    private static final Pattern faceLinePattern = Pattern.compile("^f\\s(.+)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE);
    private static final Pattern vertexValuePattern = Pattern.compile("([0-9\\-\\.]+)");
    private static final Pattern faceValuePattern = Pattern.compile("([0-9]+)");

    private List<Float> vertices = new LinkedList<Float>();
    private List<Short> faces = new LinkedList<Short>();

    public void parseVertices(String data) {
        Matcher matcher1 = vertexLinePattern.matcher(data);
        while(matcher1.find()) {
            String line = matcher1.group(1);

            Matcher matcher2 = vertexValuePattern.matcher(line);
            while(matcher2.find()) {
                vertices.add(Float.parseFloat(matcher2.group(1)));
            }
        }
    }

    public void parseFaces(String data) {
        Matcher matcher1 = faceLinePattern.matcher(data);
        while(matcher1.find()) {
            String line = matcher1.group(1);

            Matcher matcher2 = faceValuePattern.matcher(line);
            while(matcher2.find()) {
                short no = (short)(Integer.parseInt(matcher2.group(1)) - 1); // -1 due to 1 based index in OBJ files
                faces.add(no);
            }
        }
    }

    public List<Float> getVertices() {
        return vertices;
    }

    public List<Short> getFaces() {
        return faces;
    }
}

正则表达式从String中提取浮点数

1 个答案: